Prince, 22, who earned a business degree from Loyola Marymount University in Los Angeles, took to Instagram over the weekend to share a gallery of photos from his big day, including one of him and 17-year-old Bigi (whose dad called him Blanket) posing together.
In the sweet pic, Prince flashes a peace sign as Bigi — who's now taller than Prince — smiles next to him.
In his caption, Prince gushed about his college experience and thanked members of the Jackson family for helping him reach his graduation goal.
"I wish I could thank everyone that helped me make it to the end but I can’t and unfortunately they’re not all pictured here. But the biggest thanks goes to @tjjackson9 (Michael's nephew T.J. Jackson) and his brothers @tarylljackson and @tajjackson who kept pushing me to graduate and finish up my degree when I wanted to quit," he wrote.
He added, "Honestly I can’t tell you if all of it was worth it yet but I am proud of my degree as I believe it is a testament to my dedication and discipline."
Though fans haven't seen much of Bigi since his famous father's death in 2009, the publicity-shy teen also popped up last month in one of Prince's Instagram pics.
That photo found the brothers posing with a group of their pals during an outing to see "Avengers: Endgame." Bigi, in a Marvel Comics T-shirt, stands smiling in the center of the group while Prince kneels at the far left. Their sister, Paris Jackson, 21, is not in the shot.
Bigi is the son of Jackson and an unidentified surrogate mother. Paris and Prince's mother is Debbie Rowe, who was married to Jackson from 1996 to 1999.
In 2017, Prince opened up to TODAY about the special "bond" he shares with Paris and Bigi.
"Me and my siblings, we get along really well," Prince said. "Especially my sister, she's grown so much, and I think she's been able to really step up. And I don't really see myself as her older brother. It's kind of like we're equal partners when it comes down to it. And Bigi's just so mature for his age — it's a pretty strong bond."